In H.264/AVC that is one of standard specifications of image coding system, two kinds of parameter sets called a sequence parameter set (SPS) and a picture parameter set (PPS) that are used for storing parameters for coding and decoding an image are defined. The image data of each slice is classified into VCL (Video Coding Layer) NAL (Network Abstraction Layer) units, and these parameter sets are classified into non-VCL NAL units. Generally, in a case where a coded stream that is coded using the H.264/AVC system is stored in a file including a header region and a data region, the SPS and the PPS are inserted into the header region, and image data is inserted into the data region.
In a standardization operation of HEVC (High Efficiency Video Coding) that is a next-generation image coding system subsequent to H.264/AVC, introduction of an adaptation parameter set (APS) that is a new parameter set other than the SPS and the PPS has been proposed (see Non-Patent Documents 1 and 2 described below).
The APS is also one kind of parameter sets. Thus, according to an existing technique, similarly to the SPS and the PPS, the APS is also inserted into the header region of a file. Examples of a file format including a header region and a data region include an MPEG-4 Part 14 (ISO/IEC 14496-14: 2003, hereinafter, referred to as MP4) format and an MPEG-4 Part 15 (ISO/IEC 14496-15: 2004, AVC file) format.